A rash of unauthorized login attempts to numerous World of Warcraft user accounts through the website and mobile Armory app has forced Blizzard to the auction house through the app and warn players to change their logins.

A rash of unauthorized login attempts to numerous World of Warcraft user accounts through the website and mobile Armory app has forced Blizzard to disable access to the auction house through the app and warn players to change their logins.

"We're in the process of notifying any account holders who were not using an authenticator and whose account showed signs of unauthorized access (e.g., logging in from an unusual IP address)," Blizzard said on its official blog. "If you are among this group, you will receive an email describing how to reset your account."

In the meantime, Blizzard has temporarily disabled access to the auction house through the mobile app, and will be restoring gold and items to anyone affected by the breach.

The series lost about 1.3 million subscribers so far in the first quarter of this year from the 9.6 million announced after the launch of Mists of Pandaria expansion last year. Blizzard is planning to push out more frequent updates to keep players interested in the game.